linear acceleration

CMakeLists.txt

@@ -27,8 +27,10 @@ add_executable(Moer
 
  src/CoreLayer/Math/Transform.cpp
 
- src/FunctionLayer/Acceleration/EmbreeBVH.cpp
  src/FunctionLayer/Acceleration/AABB.cpp
+ src/FunctionLayer/Acceleration/Acceleration.cpp
+ src/FunctionLayer/Acceleration/EmbreeBVH.cpp
+ src/FunctionLayer/Acceleration/Linear.cpp
 
  src/FunctionLayer/Integrator/NormalIntegrator.cpp
  src/FunctionLayer/Integrator/DirectIntegrator.cpp

README.md

@@ -33,6 +33,7 @@ Moer-lite的框架基于Moer主干：https://github.com/NJUCG/Moer .
  - 修改了Triangle.cpp中的bug（之前当mesh文件不存在法线和纹理信息时会发生段错误）
  - 对AABB进行封装（见Shape::getAABB）
  - Scene::rayIntersect、Shape::rayIntersectShape、Acceleration::rayIntersect、Integrator::li中const Ray& 修改为Ray&
+ - 修改了Acceleration求交的接口，现在每个加速结构需要实现bool Acceleration::rayIntersect(Ray &ray, int *geomID, int *primID, float *u, float *v) const函数
 
 ## TODO
 - 对mesh和sphere实现表面采样（目前只有parallelogram可以配置为面光源）

src/FunctionLayer/Acceleration/Acceleration.cpp

@@ -0,0 +1,27 @@
+#include "Acceleration.h"
+#include "EmbreeBVH.h"
+#include "Linear.h"
+
+// Default acceleration type is embree
+AccelerationType Acceleration::type = AccelerationType::Embree;
+
+std::map<std::string, AccelerationType> accelerationTypeMap = {
+ {"embree", AccelerationType::Embree}, {"linear", AccelerationType::Linear}};
+
+std::map<AccelerationType, std::function<std::shared_ptr<Acceleration>()>>
+ accelerationBuildMap = {
+ {AccelerationType::Embree, std::make_shared<EmbreeBVH>},
+ {AccelerationType::Linear, std::make_shared<LinearAcceleration>}};
+
+void Acceleration::setAccelerationType(std::string type) {
+ if (accelerationTypeMap.count(type) == 0) {
+ std::cerr << "Unkown acceleration type " << type << "!\n";
+ exit(1);
+ }
+ std::cout << "Using acceleration type " << type << "\n";
+ Acceleration::type = accelerationTypeMap[type];
+}
+
+std::shared_ptr<Acceleration> Acceleration::createAcceleration() {
+ return accelerationBuildMap[Acceleration::type]();
+}

src/FunctionLayer/Acceleration/Acceleration.h

@@ -4,25 +4,44 @@
 #include <FunctionLayer/Shape/Shape.h>
 #include <optional>
 #include <vector>
+
+enum class AccelerationType { Embree, Linear };
+
 //* 所有空间加速结构的基类
 class Acceleration {
 public:
  Acceleration() = default;
 
  virtual ~Acceleration() = default;
 
+ static void setAccelerationType(std::string type);
+
+ static std::shared_ptr<Acceleration> createAcceleration();
+
+ std::optional<Intersection> rayIntersect(Ray &ray) const {
+ int primID, geomID = -1;
+ float u, v;
+ bool hit = rayIntersect(ray, &geomID, &primID, &u, &v);
+ if (!hit)
+ return std::nullopt;
+ Intersection its;
+ shapes[geomID]->fillIntersection(ray.tFar, primID, u, v, &its);
+ return std::make_optional(its);
+ }
+
  //* 所有空间加速结构需要实现的接口
- virtual std::optional<Intersection> rayIntersect(Ray &ray) const = 0;
+ virtual bool rayIntersect(Ray &ray, int *geomID, int *primID, float *u,
+ float *v) const = 0;
 
  //* 根据场景中的所有几何体构建加速结构
  virtual void build() = 0;
 
  //* 向加速结构中增加一个几何体
- void attachShape(std::shared_ptr<Shape> shape) {
- shape->geometryID = shapes.size();
- shapes.emplace_back(shape);
- }
+ void attachShape(std::shared_ptr<Shape> shape) { shapes.emplace_back(shape); }
+
+public:
+ static AccelerationType type;
 
 protected:
  std::vector<std::shared_ptr<Shape>> shapes; //* 场景中的所有几何体
-};
+};

src/FunctionLayer/Acceleration/EmbreeBVH.cpp

@@ -18,7 +18,8 @@ void EmbreeBVH::build() {
  rtcCommitScene(scene);
 }
 
-std::optional<Intersection> EmbreeBVH::rayIntersect(Ray &ray) const {
+bool EmbreeBVH::rayIntersect(Ray &ray, int *geomID, int *primID, float *u,
+ float *v) const {
  RTCIntersectContext context;
  RTCRayHit rtcRayHit;
  rtcInitIntersectContext(&context);
@@ -40,13 +41,13 @@ std::optional<Intersection> EmbreeBVH::rayIntersect(Ray &ray) const {
 
  //* 如果光线与加速结构没有交点
  if (rtcRayHit.hit.geomID == RTC_INVALID_GEOMETRY_ID)
- return std::nullopt;
+ return false;
 
  //* 有交点，填充intersection数据结构
  ray.tFar = rtcRayHit.ray.tfar;
- auto shape = shapes[rtcRayHit.hit.geomID];
- Intersection intersection;
- shape->fillIntersection(rtcRayHit.ray.tfar, rtcRayHit.hit.primID,
-  rtcRayHit.hit.u, rtcRayHit.hit.v, &intersection);
- return std::make_optional(intersection);
+ *geomID = rtcRayHit.hit.geomID;
+ *primID = rtcRayHit.hit.primID;
+ *u = rtcRayHit.hit.u;
+ *v = rtcRayHit.hit.v;
+ return true;
 }

src/FunctionLayer/Acceleration/EmbreeBVH.h

@@ -13,7 +13,8 @@ class EmbreeBVH : public Acceleration {
 
  virtual void build() override;
 
- virtual std::optional<Intersection> rayIntersect(Ray &ray) const override;
+ virtual bool rayIntersect(Ray &ray, int *geomID, int *primID, float *u,
+ float *v) const override;
 
 private:
  //* 通过RTCDevice和RTCScene调用embree

src/FunctionLayer/Acceleration/Linear.cpp

@@ -5,21 +5,18 @@ LinearAcceleration::LinearAcceleration() {
 }
 
 void LinearAcceleration::build() {
- // do nothing
+ for (auto shape : shapes)
+ shape->initInternalAcceleration();
 }
 
-std::optional<Intersection> LinearAcceleration::rayIntersect(Ray &ray) const {
+bool LinearAcceleration::rayIntersect(Ray &ray, int *geomID, int *primID,
+ float *u, float *v) const {
  // Just traverse all shapes in the scene
- float u, v;
- int primID, geomID = -1;
+
  for (const auto shape : shapes) {
- if (shape->rayIntersectShape(ray, &primID, &u, &v)) {
- geomID = shape->geometryID;
+ if (shape->rayIntersectShape(ray, primID, u, v)) {
+ *geomID = shape->geometryID;
  }
  }
- if (geomID == -1)
- return std::nullopt;
- Intersection its;
- shapes[geomID]->fillIntersection(ray.tFar, primID, u, v, &its);
- return std::make_optional(its);
+ return (*geomID != -1);
 }

src/FunctionLayer/Acceleration/Linear.h

@@ -11,5 +11,6 @@ class LinearAcceleration : public Acceleration {
 
  virtual void build() override;
 
- virtual std::optional<Intersection> rayIntersect(Ray &ray) const override;
+ virtual bool rayIntersect(Ray &ray, int *geomID, int *primID, float *u,
+ float *v) const override;
 };

src/FunctionLayer/Scene/Scene.cpp

@@ -1,15 +1,21 @@
 #include "Scene.h"
 #include <FunctionLayer/Acceleration/EmbreeBVH.h>
+#include <FunctionLayer/Acceleration/Linear.h>
 #include <FunctionLayer/Light/AreaLight.h>
 #include <ResourceLayer/Factory.h>
 
 Scene::Scene(const Json &json) {
- //* 初始化加速结构
- acceleration = std::make_shared<EmbreeBVH>();
+ //* 初始化加速结构，默认使用embree
+ std::string accelerationType =
+ fetchOptional<std::string>(json, "acceleration", "embree");
+ Acceleration::setAccelerationType(accelerationType);
+ acceleration = Acceleration::createAcceleration();
+
  //* 添加几何体
  auto shapes = json["shapes"];
  for (int i = 0; i < shapes.size(); ++i) {
  auto shape = Factory::construct_class<Shape>(shapes[i]);
+ shape->geometryID = i;
  acceleration->attachShape(shape);
  }
  //* 添加光源

src/FunctionLayer/Shape/Shape.h

@@ -31,6 +31,12 @@ class Shape : public Transformable {
  virtual void uniformSampleOnSurface(Vector2f sample, Intersection *result,
  float *pdf) const = 0;
 
+ //* 当不使用embree时，TriangleMesh需要实现内部加速结构，调用该方法
+ virtual void initInternalAcceleration() {
+ // Default do nothing
+ return;
+ }
+
 public:
  int geometryID;
  std::shared_ptr<Light> light;